USGS Topo Digitized Raster Graphics (DRG) CD Coverage for Arizona

By Jeep Experts

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Your tax {dollars} have been used over time to fund the USGS and its many tasks.  Many of you’re little question aware of the ever in style 7.5′ topo map, or quad map, that’s generally offered in map shops for about $6 every.  These maps are nice for exploring and 4 wheelin’.  These 1:24000 scale maps present good element and the 20′ contour traces yield a great view of the terrain when you get use to studying them.

However….shopping for these little maps at $6 a pop will get costly.  Unfolded, they suck up the higher a part of a Jeep’s hood and whether it is windy out, an ample provide of rocks is required as nook paper weights.  The USGS has scanned these 1000’s of maps on an digital scanner and with some applicable reference information information, made them accessible to most people within the type of Digitized Raster Graphic (DRG) photos.  The worth was initially fairly affordable, however some bean counter within the authorities determined they may promote us the outcomes of our tax {dollars} for effectively over $100 per CD.  NOT VERY NICE FOLKS!!!

Luckily, these DRG CDs might be legally copied by anybody for the reason that information on them is public area (bear in mind, our tax {dollars} funded these tasks).  A lot of corporations have began promoting these CDs on the Internet and a few have really gotten into some fairly good worth wars.  Be cautious although….as many corporations additionally use the maps from these CDs and mix them with their very own software program.  Obviously these CDs cannot be legally copied.  When these industrial corporations do that, they normally do one thing to the information information in order that these map photos solely work with their software program. 

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Each USGS CD has 64 of those 7.5′ topo maps on them, which make up a grid of 8×8 maps.  These CDs additionally include two 1:100,000 scale maps and a 1:250,000 scale map.  What makes these CDs really easy to make use of is that each one of those topos include the required information information that OziExplorer reads in order that it may  auto-calibrate every map.  What does this imply to you?  You merely load the map reference information from the CD and it is able to use…no muss, no fuss!  The scanned photos stay on the CD, except you’ve gotten BIG laborious drives (Some lap tops might have the HD capability to retailer a state’s price of information.)

The graphic under reveals the state of Arizona and the foremost 1 x 2 grids that cowl it.  Each of those 1 x 2 grids are lined by 2 CDs.  I’ve written the CD lat/lengthy numbers in inexperienced on the east and west borders of the blue grids.  For instance, Grand Canyon is roofed by 36113 and 36112.

 

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